TPS4132 Background: Cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) can improve prognosis of patients with peritoneal metastases (PM) in colorectal cancer. In gastric cancer (GC) patients with PM this concept is under debate. Perioperative chemotherapy has been shown to improve survival in gastric cancer. In patients with limited PM systemic chemotherapy, a palliative gastrectomy and CRS may prolong survival compared to chemotherapy alone (Sun) in selected patients. It is unclear whether HIPEC has an additional benefit in this setting. The GASTRIPEC trial (NCT02158988) will clarify the role of HIPEC. Methods: It is an open label, multicenter randomized phase III trial. 180 patients with histological proven GC or GE-junction and PM will be included. All patients will receive 3 cycles of pre- and postoperative chemotherapy, dependent on the HER 2 status (Her 2 + ve: cisplatin, capecitabine, trastuzumab (CCT); HER 2 –ve: epirubicin, oxaliplatin, capecitabine (EOX). A...